Process for cracking gaseous hydrocarbons



'March l, 1932. J. A. GUYER ET AL `PROCESS FOR CRACKING, GASEOUS HYDROCARBONS Filed May 24, 1928 S G E Si 35 A M2211 211D/ SP9 'Patented Mar. 1, 1932 UNITED STATES PATENT OFFICE JESSE A. GUYEP. AND lEmimimoiz E. FREY, or PAa'rLEsvILLE, oxLAoMA, AssIoNons 'ro PHILLIPS PE'rnoLEUM COMPANY, or BAR'rLEsvTLLE, OKLAHOMA, A oonPonA- TION 0F DELAWARE Y PROCESS FOR CRACXING GASEOUS HYDBOCABBONSA Application mea may 24, 192s. serial no. 230,334."

supplied bythe combustion gases is used to the best advantage.

A further object is to furnish such a system in which fuel, for instance gas high in hydrogen content is employed in creating the products of combustion in `order to obtain the greatest amount of heat per volume of products of combustion. Y

A still further object is to provide a system of this nature in which gases reformed in the system may be recycled back into the reaction chamber in cooled condition for the purpose of preventing reactions taking place therein beyond a desired exposure period.

With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the vaccompanying drawing and' more particularly pointed out in the appended claims.

The drawing shows a diagrammatic view of the improved apparatus.

Referring to the drawing, it will be noted' that the gaseous hydrocarbons to be treated, such as natural gas consisting mainly of methane, thane, propane, or butane, or any of such constituents, are passed in regulated quantities by way of the pipe (1) toa coil or the like (2) arran ed Within any suitable furnace or heater (3 The gaseous hydrocarbons after `being preheated in the furnace are 4conveyed through pipe (4) anddischarged into the reaction chamber (5) of a suitable reaction unit (6) thatis preferably insulated to facilitate the maintenance of propertemperature conditions therein.

The fuel gas (preferably one high in hydrogen content) is fed into a conduit (7) and i s nixed with air entering through the pipe This combustible mixture also flows through a coil or the like (9) directly-over the burner (11), in the furnace and is burned within the combustion chamber (10) of the reaction unit Y The furnace maybe fired by any suitable means such as a gas burner (11') From the combustion chamber, the products of combustion will rise through the brick work or the like grate( 12)y and in the reaction chamber will intermingle with the preheated gaseous hydrocarbons entering the same through pipe (4).' Conditions will be such in the reaction chamber that the reaction products will be exposed to cracking conditions for a sufficient period of timeonly to reform some of the gaseous hydrocarbons and to convert some of the same into liquid hydrocarbons.

The reformed gaseous hydrocarbons carrying the liquid hydrocarbons will be discharged from the reaction chamber by way of pipe (13). which leads the same to a heat exchanger (14) in which the reformed gases will lose some of their heat to incoming gaseous hydrocarbons if the latter are heated in the heat exchanger instead of in the furnace. To permit the raw gas to be heated in the heat exchanger, a branch pipe (15) will lead from the line 1) to the heat exchanger, and a pipe (16) will convey the preheated gaseous hydrocarbons from the heat exchanger and col discharge the same at the point (17) into the reaction chamber.

Reformed gases and the liquid hydrocarbons produced in the reaction chamber will pass by way of pipe (18) to the scrubber (19) and in the latter these products will be further cooled and relieved of any tar or carbon, which may pass out by Way of pipe (20) The reformed gases and liquid hydrocarbons purified by this means, passes through pipe (21) to yan extraction plant (22) and in the latter the reformed gases are separated from the lliquid hydrocarbons; said liquid l(1yd)rocarbons being discharged at the point Reformed gases discharged from the plant (22) by way of pipe (24) may exit through -5 conduit (25) but it is preferred to return a portion of these reformed gases inthe cooled condition in which they leave the tower (22), to the reaction chamber with a View of utilizing such cooled reformed gases as a medium for regulating the .time of exposure of the gaseous hydrocarbons to crackin conditions vwithin the reaction chamber (5 To this end, some ofthe reformed gases may be fed by pipe (26) to the reaction chamber, entering the latter at a point above the gaseous inlets (4) and (17).

It has been found that when such cooled reformed gas is introduced in the reaction chamber at such a point, it will act to dilute the hydrocarbons undergoing cracking and instantaneously cool the same so as tohalt the reaction within the chamber (5).

By preheating the fuel as, air and raw gas, and using a fuel high 1n hydrogen content, the process will deliver combustion gases to the reaction chamber having the greatest effective value perv unit volume in B. t. u. it

is possible to produce, because its full heat of combustion is available to raise the tem-` perature of the treated gases.

Preheating the gases, both fuel and raw gases under treatment, has several advan-l tages, particularly when a fuel rich in hydrogen is used and the object of the pyrolysis reaction is to convert the raw gases to fliquids and solids havin a diierent comlbined h drogen content t an the `gases themselves, or any excess hydrogen Vderived from the fuel is ready and available at the right temperature to complement the main reaction in the formation of such bodies, if needed, and is easily eliminated if not. The gases may be preheated by an auxiliary tube furnace, a heat exchanger, or the like. -In or- ,Lb der to obtain the greatest amount 4of heat .per volume of products of combustion, as before stated, it is advisable to use fuel high in hydrogen, as the product of combustion of hydrogen is water. The water being'a liquid,

at low temperatures may be readily condensed out when the gases are cooled in the heaty exchanger and scrubber.

It is believed that the fore ing explanation will enable any one familiar V`with .such processes and apparatus to'readily understand the present invention, and it is appar- 'et that details and .conditions ma be varied somewhat without going outsi e of` the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. In a process for the pyrolytic conversion, of normally gaseous aliphatic hydrocarbons- -to crude benzol, continuously passing said C5 gaseous hydrocarbons rst through an elongated passageway of restricted cross-seci action chamber.

2. In a process for the pyrolytic convexsion of normally gaseous aliphatic hydrocarbons to crudefbenzol, continuously passing said gaseous hydrocarbons in preheated condition through a reaction chamber, heating a mixture of air and fuel, controllably commingling in said chamber the preheated gaseous hydrocarbons with hot products of substantially completed combustion roduced in situ with relationto saidcham r from said mixture, for additionally heating said hydrocarbons to cracking temperatures, and separating the` crudev benzol so produced, from the ,gaseous mixture discharged from the reaction chamber.

3. In a process for the pyrolytic conversion of normallygaseous' aliphatic hydrocarbons to crude benzol, continuously passing said gaseoushydrocarbons in preheated condltion through a reaction chamber, controllably commmglingin said chamber said preheated 'gaseous aliphatic hydrocarbons with hot products of combustion reduced in situ with relation to said cham r for additlonally heating said hydrocarbons to cracking temperatures, separating the crude benzol so produced from the residual gases, and returnmg a portion of the residual gases m cooled condition to the react-ion chamber for preventing reactions taking place therein beaf yond a desired exposure period.

4. In a process for the yrol' ic conversion of normally gaseous@ ahphatlc hydrocarbons to' crude benzol, passing, while preheating, a portion of. said gaseous hydrocarbons throughy an elongated passageway of restricted crosssectional area and then into a reaction chamber, passin while preheatig another portionof sai gaseous hydrocar ns through a'second passageway and into the reaction chamber, controllably commingling in said chamber both portions of said preheated gaseous hydrocarbons with hot products of substantially completed combustion,

and thereby additionally heating said hydrocarbons to cracking temperatures, passing the cracked gases from t e reaction chamber through a third passagewa 'f inindirect heat intere finali?7 separating the crude benzol so produce 5. In a process for the pyrolytic conversion of normally gaseous aliphaticA hydrocarbons ange with the secon passageway, and

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to crude benzol, continuously passing said gaseous hydrocarbons in two streams through first and second passageways into a reaction chamber at different points, preheating said gaseous hydrocarbons as the streams flow through the passageways, preheating a mixture of air and fuel and burning saidmixture within the reaction chamber for hot products of combustion, comnnngling in ,the reaction chamber said gaseous hydrocarbons with said hot products of combustion, and thereby additionally heating said hydrocarbons to cracking temperatures, discharging the cracked gases from the reaction chamber in indirect heat exchange with the gaseous hydrocarbons flowing through the second passageway, separating the crude benzol so produced from the residual ases, and returning a portion of said resldual gases in cooled condition to the reaction chamber for preventing reactions taking place therein bey yond a desired exposure period.

JESSE A. GUYER; FREDERICK E. FREY.

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